Os ciclometalados de paládio(II) são compostos inorgânicos reativos empregados em vários estudos biológicos devido a seu potencial antitumoral e interação com o sistema imune. Neste estudo, a resposta imune e citotóxica induzida por dois complexos organopaladados: [{Pd(N,C-dmba)} 2 (μ-NCS) 2 ] (1), [Pd(C-dmba)(NCS)(dppp)] (2) [dmba = N,N'-dimetilbenzilamina, dppp = 1,3-bis(difenilfosfino)propano] e cisplatina (cis-DDP), como padrão, foram investigados em camundongos portadores do tumor ascítico de Ehrlich. Os camundongos foram divididos em cinco grupos e inoculados com (1) ou (2) ou cis-DDP ou apenas veículo ou solução salina tamponada de fosfatos (PBS). Diversos parâmetros foram avaliados, tais como a porcentagem de células tumorais presentes no exsudato peritoneal, os níveis de óxido nítrico (NO) e fator de necrose tumoral (TNF-α) séricos e o aumento na expectativa de vida. Os dados obtidos demonstram que o composto (2) apresentou atividade similar à da cis-DDP, como, por exemplo, aumento na expectativa de vida, diminuição dos níveis séricos de TNF-α e aumento da produção de NO.Cyclometallated palladium(II) complexes are reactive inorganic compounds employed in several biological studies because of their antitumour potential and interaction with immune system. In the present study, the immune and citotoxic response induced by two organopalladated complexes: [{Pd(N,C-dmba)} 2 (μ-NCS) 2 ] (1), [Pd(C-dmba)(NCS)(dppp)] (2) [dmba = N,N'-dimethylbenzylamine, dppp = 1,3-bis(diphenylphosphino)propane] and cisplatin (cis-DDP), as standard, were investigated in mice bearing Ehrlich ascites tumour. The mice were divided into five groups and inoculated with the compounds (1) or (2) or cisplatin, or only vehicle or phosphatebuffered saline (PBS). Many parameters were evaluated, such as tumour cell percentage in the peritoneal exsudate, levels of seric nitric oxide (NO) and tumour necrosis factor-alpha (TNF-α) and increase in life span. Analysis of all data revealed, for compound (2), an activity similar to that presented by cisplatin, resulting in increased life span, lower levels of seric TNF-α and increase in NO production.Keywords: palladium(II) complexes, Ehrlich ascites tumour, macrophages, nitric oxide, tumour necrosis factor-alpha.
IntroductionCancer is a disease in which unremitting clonal expansion of somatic cells kills by invading, subverting, and eroding normal tissues. 1 Millions of people die every year from the metastatic spread of cancer that occurs through blood and lymphatic vessels or directly into tissues and body cavities. 2 Between the several types of cancer, breast cancer is the most common malignancy in women worldwide. 3 In some cases, immune cells constitute a prominent component of the host response to cancer, but their participation in tumour pathogenesis remains not completely understood. Dense intratumoral lymphocyte cis-Diamminedichloroplatinum(II), 9 a clinically important antitumour drug, acts like a classical alkylating agent in chemotherapy against some types of cancers. It is a potent ...